Wireless communications services represent the fastest growing segment of the telecommunications industry worldwide. Although the Telecommunications Act of 1996 was intended to open the competitive environment in the United States, allowing many new entrants into the local access loop, growth has been constrained by several factors. Some of these factors are endemic to any communications system (limited bandwidth, high capital costs, etc.). Other constraints are imposed by the business models that have come to be generally accepted in the industry. Most land line and wireless operators typically derive the majority of their revenues and profits from a relatively few—“heavy” and “business”—users of their networks. The heavy and business user segments have come to be considered the most desirable segment of the wireless customer population, due to their relative price inelasticity. Land line providers have typically focused on business users. Accordingly, per minute of usage pricing of cellular services has been adapted to that conventional business model, which was introduced in the late 1980's. That conventional model, however, imposes constraints on operations and networks, and presents high usage charges to casual users. These patterns have, in fact, been favored by cellular operators due to the high profitability levels they offer.
A conventional wireless system of the type known prior to the present invention is described by Robert C. Raciti, in CELLULAR TECHNOLOGY (July 1995), which is incorporated herein by reference. Prior known cellular networks are typically constructed to achieve a relatively uniform level of coverage over a preselected service area. The service area is extended to a greater metropolitan area, namely, major population centers and major highway connections. Generally, the service area is specifically adapted to serve roaming traffic, which is billed at a higher rate. Consequently, roaming is favored in prior known systems. The service has been marketed on the breadth of coverage as well as complex features, targeted at the heavy and business users.
Network capacity is rationed, to avoid over use of the network, by maintaining pricing levels that tend to limit casual usage. Use is metered by price, and constrained by that pricing within the design limits of the system. When the existing wireless communications operators have looked at moving their market focus from the typical business users to a broader market, they have typically introduced prepaid services that allow the consumer to control the costs but have required very high per minute usage charges.
Wireless communications networks using this conventional business model typically comprise three basic components: Cell sites with RF base stations; Mobile Telephone Switching Offices (MTSO); and mobile phones that are provided to subscribers. Each base station contains a radio transceiver and controller, and provides radio communications to the mobile phone units operating in its cell. The cells are typically engineered into a network that is deployed in a hexagonal cell pattern, in order to provide local, regional, or national cellular coverage.
The MTSO links calls together using traditional copper, fiber optic, and/or microwave technology and acts as a central office exchange, allowing users to place a call on the local and long distance public telephone systems or mobile to mobile traffic. It allows mobile communication devices in the cell to dial out and alerts devices in the cell of incoming calls. The MTSO continuously monitors the quality of the communications signal and transfers the call to another base station that is better suited to provide communications services to the mobile device.
The mobile communication devices comprise hand-held phones, car phones, notebook computers, personal digital assistants, pen-based computers, palm-top computers, pagers, hand-held e-mail devices (such as those produced under the Blackberry™ brand), and portable data collection devices. The present inventors anticipate that, although the majority of cellular traffic has traditionally been voice communications, the relative proportion of traffic that comprises data, text, and potentially video, messages is increasing and is expected to increase dramatically in the coming years. The present invention is intended to work with all wireless communications devices. When these various types of mobile units communicate with the network, they must register with the system by subscribing with a wireless operator.
Most wireless operators of prior known systems have arrangements with other operators allowing users to roam. Roaming occurs when the mobile unit is outside the coverage area of their “home” cellular service provider and an alternative cellular provider handles the communication. Mobile units may also be connected to the Public Switched Telephone Network (PSTN) operated by an Incumbent Local Exchange Carrier (ILEC), Competitive Local Exchange Carrier (CLEC), Regional Bell Operating Company (RBOC), long distance carrier, or other telecommunications provider.
The radio spectrum used for wireless (cellular) communications comprises many bands that are allocated and used for commercial, personal, and military use. Fifty (50) MHz of spectrum is allocated to cellular networks in the 824-849 MHZ and the 869-894 MHZ bands. This spectrum has been allocated into two 25 Mhz bands and has generally been allocated to very large service providers. Other bands of spectrum have been allocated for wireless communications. PCS is a wireless communications network that operates at a radio frequency of 1.9 GHz. This spectrum has been subdivided into three 30 Mhz and three 10 Mhz bands that are used by both large service providers and many new, more innovative service providers. The allocation of radio spectrum in the United States is described in the NTIA Manual of Regulations and Procedures for Federal Radio Frequency Management, Ch. 4, at 4-4 to 4-91 (2000), which is incorporated herein by reference.
Several types of network access are available in the United States including, without limitation: Advanced Mobile Phone Systems (AMPS), Time Division Multiple Access (TDMA) (in two formats), and Code Division Multiple Access (CDMA). AMPS is the cellular standard that has been extensively deployed in North America and has been commercially available since 1983. The current cellular standard describing access methods to the network is IS-553. It divides 50 MHZ of spectrum into 832 frequency channels, each 30 KHz wide. Various organizations, such as the Portable Computer and Communications Association (PCCA), modem manufacturers, computer manufactures, and service providers, have worked together in defining the IS-553 interoperability standard.
Time Division Multiple Access (TDMA) is a digital access method that allocates time slots to different users, allowing them to share similar radio frequency channels. TDMA divides each frequency channel into six time slots and allocates two slots to each user. This time division of the carrier signal increases the network capacity by 300% (a factor of 3). Standard IS-54, currently upgraded to IS-136, describes a dual mode network access method allowing mobile units the choice of using TDMA or AMPS operation.
Code Division Multiple Access (CDMA) sends multiple messages over the same wide frequency channel that is decoded at the receiving end. Each mobile unit in a cell is assigned a different spreading sequence. This allows multiple users to share the same frequency spectrum. The use of CDMA increases network capacity by an order of magnitude (a factor of ten). CDMA network access standards are specified in standard IS-95, which is incorporated herein, by reference. TDMA and CDMA digital access methods offer superior performance in terms of higher capacity, improved voice quality, encryption for communication privacy, and integration with digital terrestrial networks.
Cellular Digital Packet Data (CDPD) is a technology standard sponsored by the RBOCs and McCaw Cellular. CDPD overlays packet switching onto the existing cellular voice network, and transmits data packets over the idle capacity. This packet overlay is based on an Internet protocol to backbone and does not need the call setup procedures that are required for switched voice calls. This makes CDPD adapted to short, bursty message applications, such as point-of-sale (POS) credit card verification, vehicle dispatch, package tracking, and e-mail. CDPD generally increases the network utilization, yet, excessive data traffic may cause interference with existing cellular calls.
There are a number of other wireless applications that may be used in conjunction with cellular telephony or separately: digital communications such as CDMA; cordless telephones; paging; specialized mobile radio (SMR); and satellite communication. Networks based on digital communications typically have a greater capacity than analog networks for carrying voice and data traffic than analog networks.
Michael E. Porter, in COMPETITIVE STRATEGY (1980), which is incorporated herein by reference, described various stages through which products progress through their life cycles: introduction; growth; maturity; and decline. Prior to the present invention, the cellular industry has remained in its growth phase. Some characteristics of Porter's growth phase are: growth in use; widening of the buyer group; improved reliability; competitive product improvements; increased advertising; increased channels of distribution; and high profit margins. The cellular industry has shared these features prior to the present invention.
There are approximately 100 million cellular customers in the United States. Cellular service is growing at a rate of approximately 1 million new customers every month. The buyer group has widened, extending the initial buyer group of large businesses to include most businesses. System reliability has improved, greatly. There have been many competitive product improvements, such as digital technology advancements, voicemail, encryption, and enhanced battery life. Cellular products and services are featured widely in advertising on television, radio, print, and on the Internet. Alternate channels of distribution are also becoming more popular. For example, retail office supply, electronic, and computer chains are actively marketing cellular phones and services. Throughout this period of growth, cellular operators have enjoyed high profit margins.
McCaw Cellular was one of the early entrants into the wireless telephone market. The business model developed by McCaw (AMPS) has come to be generally accepted as the predominant business model for rendering cellular service, at least in the United States. A typical cellular system to configuration of the type that was known prior to the present invention is described by Heith Knightson, in D1—CELLULAR NETWORK INFRASTRUCTURE—VOICE AND SHORT MESSAGE SERVICES, Telecommunications Standards Advisory Council of Canada (1997), which is incorporated herein by reference. As described by Knightson, AMPS is based on analog RF technology operating on frequencies 825-844 MHZ and 870-899 MHZ. The definitive standard for AMPS voice services is TIA IS-53 Cellular Features Description, which is incorporated herein by reference. The mechanisms to implement these services are given in TIA IS-41 Cellular Radio Telecommunications Intersystem Operations, which is incorporated herein by reference.
Prior to about 1997, AMPS was generally considered to be the main technology for providing mobile phone service. Currently, digital technologies, such as TDMA and CDMA have gained ascendancy. These digital technologies offer improved voice quality and increased capacity. Standards have been promulgated for each technology, which are incorporated herein by reference. Although the technologies for TDMA and CDMA are different from AMPS, some of the equipment, infrastructure, and standards currently deployed for AMPS may be used in CDMA and TDMA networks. The radio portions (physical layer) of the mobile phones and base stations have been modified to support these new RF technologies.
The cellular network is viewed by the PSTN as an alternative End Office, where voice traffic originates and terminates. The interface between the PSTN and cellular network operates SS7 protocols, which are incorporated herein by reference. Within the cellular network, the signaling and voice traffic operate over separate trunking facilities, just as in the land line network. The SS7 protocol is used to carry signaling information over these out-of-band common channel signaling facilities. This separation of signaling and voice traffic is also preserved over-the-air. Between the mobile phone and the base station, the Forward Control Channel and Reverse Control Channel convey signaling information. Voice traffic is transmitted over the Forward Voice Channel and Reverse Voice Channel.
FIG. 1 illustrates the relationship between the cellular network infrastructure and the PSTN in wireless communications systems of the type that were common in the cellular industry prior to the present invention. The IS-41 messages are routed via Signaling Transfer Points (STPs). The STPs handle network routing. In particular, the route to the Home Location Register (HLR) for a specific mobile phone is handled by the STP. This has the advantage that, as the network expands and ranges of mobile phone numbers are assigned to different HLRs or new ranges come into service, only the routing tables in the STP need be updated. Mobile Switching Centers (MSCs) do not need to maintain full routing tables to all other MSCs. FIG. 2 illustrates the functions and interfaces that support voice services. The interface reference points are defined in the IS-41 standard, which is incorporated herein by reference, to ensure correct interoperation of equipment.
A typical cellular system prior to the present invention was understood to comprise the following functional elements:                Authentication Center (AC): The AC manages the authentication information related to the Mobile Station (MS). The AC may, or may not be located within, and be indistinguishable from a Home Location Register (HLR). An AC may serve more than one HLR.        Base Station (BS): The BS describes all of the radio equipment at a single location used for serving one or more cells. The Base Station comprises a Base Station Controller and the Base Station Transceiver systems.        Equipment Identity Register (EIR): The EIR maintains user equipment identity information. The nature, purpose, and utilization continues to develop and the present inventors intend that all such uses to which these components may be put are considered part of the present invention. The EIR may, or may not, be located within, and be indistinguishable from a Mobile Switching Center (MSC).        Home Location Register (HLR): The HLR is the location register to which a user identity is assigned for record purposes such as subscriber information (e.g. ESN, MDN, Profile Information, Current Location, Authorization Period). The HLR may, or may not be located within, and be indistinguishable from an MSC. The HLR may serve more than one MSC. The HLR may be distributed over more than one physical entity.        Integrated Services Digital Network (ISDN): The ISDN is defined by the appropriate ANSI T1 Standards, which are incorporated herein by reference.        Mobile Station (MS): The MS is the interface equipment used to terminate the radio path at the user side. If provides the capabilities to access network services by the user.        Mobile Switching Center (MSC): The MSC provides the interface for user traffic between the cellular network and other public switched networks, or other MSCs in the same or other cellular networks.        Public Switched Telephone Network (PSTN): The PSTN is defined by the applicable ANSI T1 Standards.        Visitor Location Register (VLR): The VLR is the location register other than the HLR used by an MSC to retrieve information for handling of calls to or from a visiting subscriber. The VLR may, or may not be located within, and be indistinguishable from an MSC. The VLR may serve more than one MSC.The main feature of the cellular network voice service when compared with POTS (plain old telephone service) is the geographical mobility of the phone. The equipment and interfaces depicted in FIGS. 2 and 3 perform two main functions. First, they transmit and receive voice signals over the radio spectrum. This is primarily the function of the Base Station and Mobile Station, which occurs over the Um interface. Second, they track where each mobile phone is within the cellular network. This is called “mobility management” and is performed by the MSC, referencing and dynamically updating the HLR and VLR databases. As shown in FIGS. 2 and 3, this occurs over the C, D, B, and E interfaces.        
The interfaces and standards associated with these two functions of RF transmission and mobility management are distinct to cellular voice services. The other interfaces connect the cellular network to the existing land line telephone network (PSTN or ISDN), support authentication of users and equipment (AC and EIR), or support special features such as the Short Message Service (as shown in FIG. 3), that are not shown in the previous figures. These functions of network interconnection, security, and special services are not unique to the cellular network. Similar functions can be found in all land line telephone networks.
The generally accepted consensus standards applicable to wireless communications systems of the type known prior to the present invention are identified in Table 1, each of which standards are incorporated herein by reference:
TABLE 1Standards Applicable to Wireless Communications InterfacesApplicableStandardsCommentsInterfaceITU/ISOANSI/TIA/EIAA: BS to MSC interfacen/an/aIS-634Ai: MSC to PSTN interfaceX.25SS7IS-93-AB: MSC to VLR interfaceX.25SS7IS-41.2, IS-41.3C: MSC to HLR interfaceX.25SS7IS-41.2, IS-41.3D: VLR to HLR interfaceX.25SS7IS-41.2, IS-41.3Di: MSC to ISDN interface?T1.611IS-93-AE: MSC to MSC interfaceX.25SS7IS-41.2, IS-41.3,IS-41.4F: MSC to EIR interfacenot definednot defined;H: HLR to AC interfaceX.25SS7IS-41.2, IS-41.3Q:X.25SS7IS-41.2, IS-41.3Um: BS to MS interface, whichn/an/aIS-54-Bcorresponds to the air interface(TDMA and AMPS),IS88 (NAMPS)IS-95-CDMANotes:SS7 refers to the ANSI standards T1.111, T1.112 and T1.114.X.25 refers to ITU Recommendation X.25 and ISO 8878, ISO 8208 and ISO 7776.
Consensus standards for wireless communications networks have been promulgated by various bodies. Table 2 identifies the most prominent standards, each of which are incorporated herein by reference.
TABLE 2Wireless Communications StandardsANSI/TIA/EIA Standards:TIA/EIA-660Uniform Dialing Procedures and Call Processing Treatmentfor Cellular Radio Telecommunications;Telecommunications Industry AssociationTIA/EIA-664Cellular Features Description; TelecommunicationsIndustry AssociationTIA/EIA/IS-93Cellular Radio Telecommunications Ai - Di InterfacesStandard; Telecommunications Industry AssociationTIA/EIA/IS-41-C.1Cellular Radio Telecommunications IntersystemOperations: Functional Overview; TelecommunicationsIndustry AssociationTIA/EIA/IS-41-C.2Cellular Radio Telecommunications IntersystemOperations: Intersystem Hand-off Information Flows;Telecommunications Industry AssociationTIA/EIA/IS-41-C.3Cellular Radio Telecommunications IntersystemOperations: Automatic Roaming Information Flows;Telecommunications Industry AssociationTIA/EIA/IS-41-C.4Cellular Radio Telecommunications IntersystemOperations: Operations, Administration, and MaintenanceInformation Flows and Procedures; TelecommunicationsIndustry AssociationTIA/EIA/IS-41-C.5.Cellular Radio Telecommunications IntersystemOperations: Signaling Protocols; TelecommunicationsIndustry Association”TIA/EIA/IS-41-C.6Cellular Radio Telecommunications IntersystemOperations: Signaling Procedures; TelecommunicationsIndustry AssociationTIA/EIA/IS-732Cellular Digital Packet Data Specification;Telecommunications Industry Association.TIA/EIA/IS-634800-MHZ A-Interface Supporting AMPS, NAMPS,CDMA, TDMA Air Interfaces; TelecommunicationsIndustryAMPS:EIA/TIA-553Mobile Station - Land Station Compatibility specificationCDMA:TIA/EIA/IS-95A Mobile Station-Base Station Compatibility Standard forDual-Mode Wideband Spread Spectrum Cellular System;Telecommunications Industry AssociationTIA/EIA/IS-97Recommended Minimum Performance Standards for BaseStations Supporting Dual-Mode Wideband SpreadSpectrum Cellular Mobile Stations; TelecommunicationsIndustry AssociationTIA/EIA/IS-637Short Message Services for Wideband Spread SpectrumCellular System; Telecommunications Industry AssociationDMH:TIA/EIA/IS-124Cellular Radio Telecommunications Intersystem Non-Signaling Data Communications (DMH);Telecommunications Industry AssociationNAMPS:TIA/EIA/IS-88Mobile Station - Land Station Compatibility Standard forDual-Mode Narrow Band Analog Cellular Technology;Telecommunications Industry AssociationTIA/EIA/IS-91Mobile Station - Base Station Compatibility Standard for800 MHZ Analog Cellular; Telecommunications IndustryAssociationTDMA:TIA/EIA/IS-54-BCellular System Dual -Mode Mobile Station- Base StationCompatibility Standard; Telecommunications IndustryAssociationTIA/EIA/IS-136800 MHz TDMA Cellular- Radio Interface - Mobile Station - BaseStation Compatibility Standard;Telecommunications Industry AssociationANSI T1 Standards:T1.111Signaling System Number 7 - Message Transfer Part (MTP)T1.112Signaling System Number 7 - Signaling Connection ControlPart (SCCP)T1.114System Number 7 - Transaction Capabilities ApplicationPart (TCAP)T1.611Signaling System Number 7 (SS7) - Supplementary Services forNon-ISDN-SubscribersT1.209Operations, Administration, Maintenance, and Provisioning (OAM&P) -Network Tones and AnnouncementsITU-T Standards:T.50International Reference Alphabet (IRA) formerly Alphabet No.5 (or IA5)Other Related Documents:SR-TSV-002275Notes on the LEC Networks; Bell Communications Research Inc.TR-NWT-000776Network Interface Description for National ISDN-1 Customer Access;Bell Communications Research Inc.In addition to the above services, many wireless communications networks also feature Short Message Service (SMS). SMS includes the following additional elements:                Message Center (MC): The MC stores and forwards short messages. The MC may also provide supplementary services for Short Message Service.        Short Message Entity (SME): The SME composes and decomposes short messages. The SME may be implemented in many ways, such as an operator assisted service or interactive voice response service. An SME may, or may not be located within, and be indistinguishable from, an HLR, MC, VLR, MS, or MSC.The interface reference points in FIG. 4, which support the Short Message Service, are:        Interface M is the SME to MC interface;        Interface N is the MC to HLR interface; and        Interface Q is the MC to MSC interface.        
FIG. 3 depicts a cellular network, of the type known prior to the present invention, which further comprises a Message Center (MC) and Short Message Entity (SME), in addition to the infrastructure shown in FIG. 2. SMS is a data service available over the AMPS network. It is defined in IS-41, and is included under voice services because it is an integral part of the IS-41 specification. SMS allows a single packet of data to be transmitted to or from a mobile phone. SMS does not require packet fragmentation or re-assembly. Message integrity must be maintained across all interfaces, including the air (Um) interface. The SMS attempts to deliver the message whenever the mobile phone is registered on the cellular network, even when the phone is engaged in a voice or data call.
By early 1998, although the market continued in what Porter defines as its growth stage, some of the constraints imposed by the accepted cellular operation model had become apparent to the present inventors. Existing cellular business models in the United States had become stagnant. Only one business model as the McCaw, “AMPS” model—had come into widespread use and the growth of the wireless market had been limited to relatively price-insensitive users based upon that model. Accordingly, the present inventors perceived that known business methods limit future growth. These constraints include price, access to credit-challenged users, ability of users to control their monthly expenditures under prior billing models, high network operating costs, high back office support costs, high capital costs, low capital utilization, and other related limitations.
Capacity constraints were widely perceived to be a problem. Yet, the only apparent technical solutions were approaches to expand peak system capacity. Techniques to utilize existing capacity more efficiently, or using emerging technology through modification of the business model, were unknown.
For example, Motorola and Qualcomm have both been very active in advancing the development of cellular technology. Kaschke, et al., U.S. Pat. No. 6,078,821, discloses a cordless radiotelephone system having an extendable geographic coverage area and a method therefor. Cukak, et al., U.S. Pat. No. 6,058,106, discloses a method for providing a centrally coordinated peer-to-peer wireless communications network. Smith, et al., U.S. Pat. No. 5,432,780, discloses a high capacity sectorized cellular communication system. Willkie, et al., U.S. Pat. No. 5,956,651, discloses a cellular telephone interface system for AMPS or CDMA data services. None of these solutions, however, sought to resolve any capacity limitations through modification of the basic McCaw-type, cellular business model, described above.
Hence, prior to the present invention, entrenched business and pricing models limited the attractiveness of cellular services primarily to business users, who were relatively insensitive to pricing. Average Revenue Per User (ARPU) of many cellular operators of these systems had stagnated. Most cellular networks were employing the same business and technical models, resulting in little relative differentiation between cellular operators. Operators typically resisted the incorporation of new technology. Changes in one portion of a regional or nationwide network could have implications for the entire network. Although most systems had been built to a relatively high peak capacity level, average capacity utilization in most systems was relatively low. Capital utilization was low. Customers were severely segregated based upon pricing. Pricing, in turn, tended to restrict usage.
The cellular industry typically characterizes usage patterns based upon the number of minutes a phone is used each month. Table 3 below, identifies typical usage patterns by the number of minutes used per month:
TABLE 3Traditional Market Segmentation Prior to the PresentInvention Based upon Minutes of Usage (MOU)UsageMinutes of Use per MonthAverage Revenue per UserVery Heavy>500>$100Heavy400-500min./mo. >$75Business200-300min./mo.$40-75Consumer100-150min./mo.$25-40Mass Market15-20min./mo.$15-25
In a cellular network of the type known prior to the present invention, the Mass Market customer group was considered sensitive to price, relative to heavy users. Prior to the present invention, due to the deficiencies of the generally accepted business model for cellular operations, marketing efforts were not generally devoted to this customer segment. Yet, this lowest customer segment (in terms of usage and ARPU) is also the most numerous. Customer growth of most systems, therefore, was inherently limited by their business models. Design limitations prevented them from expanding into the mass market.
These pricing constraints, and resulting constraints on overall usage, were simply accepted by most operators. These constraints enabled operators to reduce the overall system capacity to a lower relative level, with the anticipation that consumers would shift their personal economics to afford these pricing constraints. Yet, this model did not avoid the substantial capital cost of building networks to service peak capacity levels. Moreover, due to the slowness of incorporating new technologies, voice quality of cellular networks was generally considered inferior to that of wire line networks. Hence, the prior known cellular operations business models had failed to deliver cellular services to the mass market, to improve quality, to reduce peak capacity and, therefore, the capital requirements on system networks, or to increase overall capacity utilization.
Other business approaches had been tried but these too failed to deliver the benefits of the present invention. For example, in about 1995, PHS introduced in the Japanese market a strategy of pricing below other cellular providers and close to wireline providers. PHS was successful in so called “telepoint” applications in which subscriber density is very high. William Webb, UNDERSTANDING CELLULAR RADIO (1998), at 183-190, which is incorporated herein by reference. The business model was well-received by consumers and the service enjoyed strong initial market penetration. The user demographics shifted rapidly from traditional business users to a mass market demographic user profile. Nonetheless, the PHS business model failed to deliver the unique advantages of the present invention for several reasons, including without limitation: unpredictability of the monthly costs; poor service quality do to inferior technology; and churn.
Users employed the service for brief periods, then abandoned it. This churn left the system operators with high initial costs of securing new customers and an insufficient time of retention of those customers to recover the acquisition cost through monthly service charges. This experience merely reinforced the conventional wisdom that the dominant business model, relatively high-priced cellular service through a network designed based upon coverage and designed to a high peak capacity usage, was the appropriate business model for wireless communications services.
Cellular networks have been deployed that incorporate some of the high capacity features of the present invention, but these networks have been operated on the business model of prior known systems. For example, networks have been deployed in both Korea (Seoul) and Hong Kong that employ additional carrier signals to boost system capacity. Prior known cellular systems typically employed a single carrier signal. Adding additional carriers substantially increases system capacity.
These two high capacity Asian cellular systems, are heavy usage CDMA systems designed around a convention cellular usage model, of the type known prior to the present invention. For example, the Seoul, Korea system features up to 6 carriers, on a CDMA network, using a substantial number of frequencies. The system is operated by SK Telecom and serves the metropolitan area in Seoul. Hong Kong had an AMPS and TDMA network. Hong Kong deployed the first CDMA network system. It, too, features numerous carriers and extremely high call capacity, due to the density of downtown Hong Kong.
Both of these known, high capacity systems, however, employed a conventional business model, operations method, network and systems approach. They are designed and operated based upon coverage, rather than capacity. They do not employ the “wireline call model” of the present invention. They do not include the business method, operations, network, and/or systems improvements to address capacity, namely, providing service primarily where people live, work, and play. Although these high-capacity networks in Seoul and Hong Kong featured multiple carriers and substantially more capacity than prior known systems, they did not include other of the unique features of the present invention. They are both “metered capacity” models, in which usage is billed based upon the number of minutes used.
As a result of the extensive experience of the cellular industry, by early 1998, the generally accepted business model for operating a wireless communications network involved: primary business users, numerous additional features for which surcharges applied, relatively high ARPU, and widespread system coverage to secure additional revenues from roamers passing through the system and paying higher roaming surcharge rates.
Neil J. Boucher, in THE CELLULAR RADIO HANDBOOK (1990), which is incorporated herein by reference, discloses a typical demand curve for a wireless system of the type known prior to the present invention. That curve is depicted in FIG. 4. Such a prior known wireless system has two peak times during the day. These occur at approximately 11 am and 7 pm, as illustrated in FIG. 4. In addition, the changes in demand from peak time to low-usage time are significantly high. In contrast, the demand curve for a wireless system according to the present invention, as shown in FIG. 5, is relatively flat and does not have the peaks and significant deltas in demand that occur in prior known wireless systems. FIG. 5 illustrates a typical busy hour utilization of a preferred embodiment of a wireless system according to the present invention.
In 1997, the present inventors began development of a new business model for delivering wireless communications services. The present inventors developed a new method, operations, network, and system for delivering wireless communications services. This invention offered low cost cellular service to a more numerous mass market, rather than merely to a limited submarket of relatively price insensitive business users.
Prior known wireless communications operators typically targeted only high-end market segments, namely, heavy users and business users, and not the consumer or mass markets. ARPU values in the consumer ($25 to 40) and mass market ($15 to 25) were generally understood to be substantially lower than ARPU's for business users ($40 to 75) and heavy users (>$75). There was no motivation to target lower ARPU customers prior to the present invention. Addressing these consumer and mass markets through prior business models would result in higher capital and customer acquisition costs, lower revenues, and lower profitability. Nor was it obvious that increasing market penetration in these consumer and mass market segments would increase revenues. Particularly in view of the, high initial cost of acquisition and high operating costs of most cellular systems, customers at the low ARPU levels associated with the consumer and mass markets would have to be retained for long periods of time. Thus, the prior known business methods, operations, networks, and systems failed to address the unique problems addressed and resolved by the present invention.
The present inventors conducted extensive studies of the demand for cellular services. Based upon these investigations, the present inventors discovered that there were several basic flaws and omissions in the prior known business methods for delivering cellular services. Specifically, rather than being an unprofitable customer segment, the mass market and consumer markets could be viable, provided sufficient costs were driven out of the cellular operation.
This had not been done by prior known business methods. The present inventors discovered that, contrary to the conventional view, as unit price and monthly service fees fell, consumer interest (in the mass market and consumer market segments) increased to relatively high levels of penetration that would support a viable business model.
In order to be profitable, however, additional costs must be driven out of the traditional method of delivering cellular services. Specifically, the high operating costs, high capital costs, and relatively low capacity utilization characteristic of prior known systems each impeded the efficiencies necessary to serve these additional market segments. As the market had already demonstrated, the requisite degree of cost savings was not possible using the prior known methods of rendering cellular services.
The present inventors identified several critical factors in achieving the cost savings necessary effectively to expand cellular service to these additional market segments: improved capacity utilization and reduced peak system capacity; targeted area coverage; unproved capital utilization; channels; reduced interconnect costs; improved back office operating efficiency; and improved network operating efficiency.
Particularly in view of a number of recent technical advances, capacity is highly dependent on the network technology employed. Webb, at 101-149, which is incorporated herein by reference. Several advances in recent years have enabled operators to enhance capacity from existing bandwidth and use bandwidth more efficiently, although other operators preferred legacy technology and the associated capacities. The present inventors believe that CDMA technology offers certain capacity advantages relative to rival technologies. Specifically, through the use of CDMA technology, the capacity of the system could be increased by a factor of two in terms of calls per sector, relative to rival technical formats. Similarly, the data rate can be increased from about 8 k to over 100 k, with projections of up to 2.4 Megabits per sector. The present inventors anticipate continued advances in network capacity.
Coverage is one of the primary design criteria for any cellular network. Prior known networks are designed to provide extensive coverage for the basic service area, as well as for the surrounding area and major transportation arteries. Although the cost of this additional coverage is substantial, revenues from roamers entering the system and using this extended coverage area typically defray the added cost and generate substantial additional revenues in prior known cellular systems. The capacity and signal strength are optimized for coverage, and in particular, in-vehicle use. In addition, the capacity of prior known systems is typically built out to the peak demand of the system, throughout the service area. Although this results in higher capital cost, that capital cost is typically recovered through roaming charges.
The present inventors, however, have designed the system coverage based upon extensive market studies identifying patterns of living, working, playing, shopping, and schooling (“live, work, and play”) of the primary service area. The system is designed to provide strong signal coverage, tailored to the usage pattern in each cell in the primary service area. The system of the present invention is preferably designed for in-building, as opposed to merely in-vehicle use. No capacity is built into an extended service area or arteries. System coverage is designed specifically for local service, without regard to roaming. Nonetheless, major interconnection arteries are covered by the service of the present invention.
This provides two benefits. First, the coverage area of the present invention is typically more limited than coverage of systems of the type known prior to the present invention. FIGS. 8 and 9 are maps depicting coverage patterns of a system prior to implementation of a system according to the present invention and after such implementation, respectively.
Second, rather than building peak system capacity throughout the coverage area, the present invention tailors capacity within each cell to expected local traffic patterns. This allows a reduction in system cost. Fewer cells are built and the capacity of the cells that are built is increased relative to prior known systems. The present inventors believe that this approach enables the system to achieve effective coverage for the service area with only about 80% of the number of cell sites of prior known systems, when sites that are related primarily to highway and roaming coverage are removed.
Capital utilization is also enhanced by the present invention as the reduced coverage sites are provided and the cost of capacity is reduced through the use of CDMA technology. In a preferred embodiment of the present invention, the capital expenditure per subscriber is reduced, from 12 to 25% of the capital expenditure per subscriber in year 1 relative to prior known systems, to 25 to 50% of the cumulative capital expenditure per subscriber in year 10. Moreover, due to the higher capacity utilization of the present invention, the difference between the present invention and prior known systems in terms of cumulative capital expenditure per unit of usage is even more substantial. The present inventors estimate that cumulative capital expenditure per unit of usage (Erlang) in year 1 preferably is only about 5% to 15% of prior known methods. In year 10, it is as low as one half.
Based upon these factors, the break even point for a network of the present invention is substantially sooner than for a network of the type known prior to the present invention. In the preferred embodiment of the present invention, the break even point is 12 months, as shown in FIG. 19. The calculations illustrated in FIG. 19 are based upon the “Typical PCS Company” model, as disclosed by the firm Donaldson, Lufkin & Jenrette IN THE GLOBAL WIRELESS COMMUNICATIONS INDUSTRY (1999), which is incorporated herein by reference: The present invention may achieve break even at the end of year one, relative to year three in systems of the type known prior to the present invention.
Channel costs of marketing cellular services comprise one of the most significant cost elements for a cellular network. Cellular services of the type known prior to the present invention are typically highly diversified and segmented, featuring highly complex pricing plans and usage models. The selling activity requires highly trained customer service representatives to explain the various phones available, their features, and the relative benefits and disadvantages of the various service plans relative to a particular customers usage pattern. All of this adds substantial selling cost to a wireless operator. The present invention, in contrast, features one or two phones, a simple plan, and high volume usage. Rather than selling through specialized channels, the present invention may sell through mass merchandise outlets. Advertising and marketing efforts are oriented to the point-of-sale and limit sales personnel involvement. Each of these features further reduces the selling expense associated with the present invention.
Interconnect costs represent a significant cost factor to the system operator in systems of the type known prior to the present invention. Specifically, when users are charged by the minute, they tend to leave their phones off when they are not placing a call in order to avoid receiving charges for unwanted calls, or they avoid giving callers their phone number. This results in the system operator generating far more outgoing calls than are received within the system. In a typical cellular system of the type known prior to the present invention; the balance between calls generated by the user and calls received is approximately 75% outgoing; 25% incoming. This means that there is a greater chance of the user making a call to a number outside the service area than of receiving one from outside the service area. Interconnect charges, therefore, tend in the direction of the system operator having to pay to operators of other systems fees for outward bound calls made from users within the system.
The present invention, however, seeks to reduce substantially interconnect charges by modifying the user's calling patterns. As the user enjoys unlimited use, without any additional charges for that higher use, the user tends to leave their phone on, even when they are not making a call. The present inventors have observed that usage patterns tend to be more balanced, in the range of 60/40 (20 point difference), in contrast to the 75/25 (50 point difference) balance observed in prior known systems. The present inventors believe that, over periods of several years, usage would migrate toward a balance of 55/45 or 50/50 in a preferred embodiment of the present invention. At that point, the interconnect charges will offset one another, eliminating this cost from the system.
Enhanced network operating efficiencies are another feature of the present invention providing a benefit relative to prior known systems. These benefits may include: reduced direct labor costs; reduced lease costs as a result of fewer, higher capacity cell sites; simplified operations; and improved back office operating efficiencies.
The present invention allows the operator to reduce the total number of cells in the system. This employs less expensive capital equipment and improves the efficiency of maintenance and repair activities, as both fewer cells are used and distance for traveling to the outlying cells that have been eliminated is reduced. As fewer cells are built into the system, lease costs are reduced for cell towers and cell sites. The cost of the fixed network and facilities are reduced relative to systems of the type known prior to the present invention.
The operating model of the present invention is preferably based upon monthly, bill-in-advance, pay-in-advance service, which is different then the pay-in-arrears system generally used for credit-worthy business customers or the prepaid system typically used for consumers. The operator, therefore, is not dependent on variable usage patterns, which result in fluctuating revenues. Revenues are based upon service and not the specific features employed from call to call. The revenue stream is leveled, offering the operator greater predictability and certainty.
Back office expenses are reduced dramatically, relative to prior known systems. One of the largest operating cost elements in prior known systems is customer service to handle billing inquiries. A typical cellular billing statement itemizes every call and details the various features (roaming, call waiting, etc.) accessed. This level of detail typically generates billing questions and challenges, all of which must be handled in a person-to-person discussion with the customer service department. The cost of handling this call volume can be one of the largest single cost elements in the back office operation of a typical prior known system. The present invention, however, eliminates these expenses. Credit checks are unnecessary. Account receivable balances are not permitted to accrue. As service is flat rate and pre-paid, there are no charges based upon the number of calls, length of calls, and features accessed. Itemized billing statements may be eliminated and replaced by simple flat rate bills. Accounts receivable and collection activities are eliminated, further simplifying back office operations.
Further, the present invention substantially reduces activation-related costs. The phones of the present invention are sold preactivated. Each phone already has loaded into it a unique cellular number upon leaving the factory. This reduces the effort required to activate. Rather than supplying skilled customer service personnel to assist in activation, activation may be conducted by the customer upon leaving the store. This Over the Air (Activation) Subscriber Provisioning (OTASP) feature of the present invention substantially reduces operations costs, and simplifies the customer's role in activating the phone. OTASP results in substantial cost savings to the system operator.
None of these improvements were obvious at the time the invention was made. In contrast, the incumbent business model has been and remains based upon minutes of usage, the time of day, and features accessed. Absent substantial elimination of costs from the existing model, the shift to lower ARPU users is not desired by system operators.
By combining these features in various combinations, to expand capacity utilization and reduce systems, capital, and operating costs, the advantages of the present invention are fully achieved.
In his recent book, Webb presents a simple and accessible primer on wireless communications systems. William Webb, UNDERSTANDING CELLULAR RADIO, Artech House, Inc. (1998), which is incorporated herein by reference. Webb describes a number of generally accepted network design factors prior to the present invention. Webb notes that prior known systems provided only enough capacity for the expected number of subscribers; if needed, additional capacity would be built into the system at a later date. Webb confirms, that prior to the present invention: “[t]o minimize system cost and roll-out time, operators need to insure that they use the fewest number of cell cites possible to provide the required coverage. The problems would be familiar to the cellular operators who expend considerable time and effort planning their networks to use the minimum number of base stations for the required coverage.” Id. at 95. Webb further teaches that in cases where there was not sufficient capacity in the network, “the cells had to be made smaller.” Id. at 98. Webb amplifies that “microcells are the only way to improve capacity in city centers.” Id. at 99.
Yet, the present inventors have adopted a different approach to network design. By designing for capacity, rather than coverage, the present inventors have been able to further reduce the number of cells, without deploying substantial numbers of microcells. The present inventors have found that, by aggressively managing the cost of their wireless communications services and deploying appropriate technology, preferably CDMA technology, they have been able to increase capacity utilization of the network, dramatically reduce their operating costs, pass substantial savings on to the consumer (who enjoys not only greater access to their wireless communications service, but does so at a lower price), and enjoy ample margin to run the business profitably on a sustaining basis.